Absolutely appreciate your opinion too and it makes sense what you say. It's a nice problem to have in terms of making such decisions and if I only keep the car until next summer and get the diamond cut ones and ensure they are well sealed etc, I might take a chance purely for aesthetics but definitely good points to consider.
I tend to keep my cars 4-5 years, so the likelihood of being able to keep a set of diamond cut wheels looking factory fresh for that period of time is nigh on impossible, taking into account tyre changes and winter road conditions. My previous car had diamond cut alloys and in spite of them being cleaned every 7-10 days and regularly sealed and waxed, and any stone chips attended to pretty much as soon as they happened, two of the wheels succumbed to white worm corrosion around the centre caps at two and a half years old. I put the onset of white worm down to poor / insufficient lacquer coverage around the edge of the wheel’s centre bore which would’ve been hidden by the edge of the centre cap. If I’d levered out the centre caps from the front of the wheel (which I wouldn’t do) and damaged the lacquer coating in the process I could understand it, but I’d never removed the centre caps from the wheels, nor had they been removed by tyre fitters as the car still had the original tyres on.
My current car had diamond cut wheels when I took delivery and those wheels were changed after about 3 months of ownership for a more durable set of anthracite powder coated / painted wheels. Four years later, they still look pretty much like new - something I doubt I could claim if I’d left the diamond cut wheels on.
I agree that diamond cut wheels do have great ‘bling’ appeal, so from an aesthetic point of view will appeal to many. Also the durability of a set of new diamond cut wheels ought to be OK until next summer, although if you need new tyres or puncture repairs during that time, I’d recommend you choose your tyre fitters wisely!